1. Field of the Invention
The invention relates to a crimping terminal fitting, a method of forming it and a wire with a terminal fitting.
2. Description of the Related Art
Japanese Registered Utility Model Publication No. 3005065 discloses a terminal fitting that is crimped and connected to an end portion of a wire. Terminal fittings of this type are used for wiring in automotive vehicles and the like.
This crimping terminal fitting includes a wire barrel to be crimped and connected to core strands of a wire and an insulation barrel portion to be crimped and connected to an insulation coating of the wire. Both barrels initially are open and are produced by press-working a single metal plate. The wire barrel includes two core crimping pieces. The core crimping pieces are deformed inwardly to wrap around the core strands of the wire and the leading ends of the core crimping pieces thrust themselves between the core strands to complete the crimping.
The thickness of a metal plate material used to produce a terminal fitting of this kind is determined in view of mechanical strength required for the terminal fitting. On the other hand, the size of a wire to be connected with the terminal fitting by crimping is determined in view of current capacity. Thus, the plate thickness of the terminal fitting becomes relatively excessively large as compared with the wire size if the current capacity is small even though a relatively high strength is required.
A metal plate material with a uniform thickness has been used for terminal fittings. Thus, a relatively thick wire barrel is crimped and connected to thin core strands of a wire and the leading ends of the wire barrel cannot properly thrust themselves between the core strands. Thus, there are problems of increasing contact resistance with the wire and decreasing a wire holding force. An extremely large number of crimping terminal fittings of this type are used per vehicle. Accordingly, further weight saving have been requested as a part of weight saving of the entire vehicle.
The invention was developed in view of the above situation and an object thereof is to provide a light weight crimping terminal fitting that can be crimped and connected properly even to a thin wire.